U.S. Pat. No. 3,535,964 discloses a tool used to produce pockets in a roller cage. The tool includes a U-shaped profile tool having parallel legs that are designed as male dies for punching. The pockets in the roller cage that are immediately adjacent one another and separated by a web are punched out in their full length and full width. In the punching operation, the outer cutting edges of the male dies pointing in the circumferential direction leave behind a peripheral portion that initially defines the pocket, while the inner cutting edges of the dies perform the final cutting of the runup face for the rollers.
Once the cage has been indexed onward in a one pitch increment, at the same side face of the web where the outer cutting edge of the male die was already operative, as described above, the inner cutting edge of the dies comes into use to remove an extremely narrow edge of the web side face to thereby form this web side face identically to the second one of this pocket. Because of the slight width of material that is removed, which tapers even further toward the wall thickness, major smearing of the cage material on the web side face occurs. This is undesirable as this side face of the cage is supposed to be precisely guided on the roller. Another disadvantage associated with this known tool is that the smearing also cause seizing of the male dies upon their removal from the pocket, as a result of which the webs can become deformed. A further disadvantage of the known tool is that particularly in cages of relatively large diameter, it is not possible to have an adequate inclined position of the guide faces to achieve radial holding of the roller. This is particularly true of needle cages provided with rather narrow webs.
Another drawback is that in the intended punching direction from the outside inward, because of the curvature of the cage, massive obtuse punching burrs protrude and can be removed only with great effort.
In addition to the foregoing problem, the known tool also has a graduation over the length of the pocket, in order to form retaining protrusions on the edges near the side ring that act in the opposite radial direction.
In light of the foregoing, a need exists for an apparatus and method for punching pockets in a roller cage and a correspondingly produced roller cage, in which the web side faces can be made without post machining.
A need also exists for an apparatus and method that can punch pockets in a roller cage and a correspondingly produced roller cage, in which the web side faces are dimensionally precise and have a substantially perfect sliding face surface.
It would also be desirable to produce an apparatus and method that can punch pockets in a roller cage and a correspondingly produced roller cage, in which the punching and formation work can be done without seizing of the male dies.
A need also exists for an apparatus and method that can punch pockets in a roller cage, and a correspondingly produced roller cage, in which sufficiently inclined web side faces for the sake of retaining functions are attainable.